Arc-light electrode.



W'bnesses W Ber egold Monascb.

B. MONASCH.

ABO LIGHT ELECTRODE.

Arruurnon nun 1mm, 100a.

1,010,942. Patented Dac.5, 1911.

In H I! u lii l i i m MIMI- lrwenbor' W by metal tube and the other BEB'IHOLD MONASCH,

OF BERLIN, GERMANY, KSSIGNOB TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ABC-LIGHT ELEOTRODE.

Specification of Letters Patent. I

Patented Dec. 5, 1911.

Application filed January 2, 1908. Serial No. 409,040.

To all whom it may concern:

Be it known that I, Bmrrnou) MONASCH, a subject of the King of Prussia, residing at Berlin, Germany, have invented certain new and useful 1 mprovements in Arc-Light Electrodes, of which the following is a specification.

My invention has reference to improvements in arc lights and electrodes for the production of flaming arcs.

Metallic oxids that are fairly good conductors in the cold state have heretofore been used as are electrodes, es ecially as cathodes, but the. metallic oxid w ich, of all others, has the greatest light-giving power, namely, titanium oxid or rutile, has heretofore been used only sparingly and as an ad mixture to other oxide or other materials that are fairly good conductors in the cold state. The reason for this sparing use of titanium oxid was the rather high specific resistance of rutile in the cold state, which is so great that this substance is sometimes, although erroneously, spoken of as a nonconductor. I have found, however, that titanium oxid can be used with great advantage as an electrode in an arc lamp without the admixture of other, better conducting materials, if provision is made for establishing the arc; and I have found that by simply inclosing the rutile in a metal tube, and establishing the are between the electrode, the arc will promptly shift from the metal sheath to the rutile, and will be maintained without difficulty, especially when a current of higher voltage is employed than has heretofore been deemed commercially practicable. I have obtained excellent results by the use of such electrodes with current aving a voltage of 220 volts and the light produced in this manner is whiter, and with the same amount of current, far more intense than when rutile is only employed sparingly as an admixture to other materials.

Where metallic oxids, especially iron oxids, such as magnetite with or without the admixture of rutile, are used in the formation of cathodes, the anodes are preferably made of metal, and I have found that an iron anode can be advantageously used'if made of sufficiently large cross-section so as to have the same degree of heat conductivity as the copper anodes which have heretofore been used; this is especially true when rutile preponderates in the cathode. But with the employment of iron anodes in conjunction with such cathodes a great inconvenience has heretofore been experienced by the freezing together of the anode and the molten pool which forms at the end of the cathode, when the two electrodes come together upon the interruption of the current. In that case there is formed at the junction of the two electrodes an alloy or mixture of the metal oxids of the cathode with the metal of the anode, and when the pool congeals, as it readily does, the two electrodes are frozen together, and it has heretofore been found diflicult to separate'them upon reestablishment of the current.

I have discovered that the alloy or mixture of metal oxid and iron which forms at the junction of the two electrodes is not a thoroughly coherent mass but is more or less honeycom ed, and incoherent, and when rutile is the reponderating or sole material of the catho e, the honeycombed junction of the two electrodes has a very high specific resistance, so that upon restablishment of the circuit, only little current will pass the junction. But I have also found that if a current of much higher voltage than has heretofore been used is employed, sparks will pass through the interstices in the honeycombedalloy, rendering the portions immediately affected conductlve, and gradually but rapidly heating the junction until the same melts, so that the ordinary arc-establishing mechanism is now capable of separating the electrodes and establishing the are. I have found that by the employment of current of 220 v. no difliculty is experienced inseparating the frozen electrodes and establishing the arc.

By the use of an iron'anode in conjunction with any cathode of much smaller diameter, as would be the case when the cathode is made of metal oxids, another difficulty arises from the fact that in the end of the iron anode a crater of considerable depth and rather steep slope is formed. The consequence of this is that when the current is interrupted and the two electrodes come together rather f0rcibly,.the cathode becomes mechanically wedged in the crater of the anode so that it is now quite diflicult to sepa-- rate the electrodes upon reestablishment of the current, irrespective of the freezing together of the electrodes. This .ditliculty I have overcome by forming the iron anode with a central core of copper or other metal which does not consume as rapidly as the iron, and thus prevents the formation of a deep and steep crater.

My invention therefore embraces an arc electrode formed of titanium oxid without any considerable admixture of other materials, incased in a metal sheath, preferably of iron; it also embraces the combination of such electrode or of any other electrode made principally of metal oxid, as a cathode with an iron anode in a circuit of abnormally hi h voltage; and it also embraces the com ination of a cathode giving a flaming arc, with an iron anode having a central core of copper or other metal which consumes less rapidly than the iron.

in further explanation of my invention, reference is here made to the accompanying drawing, which shows in longitudinal section and in diagram the combination of two are electrodes in accordance with my invention. 7

In this drawing 1 isthe cathode and 2 the anode. The cathode is constructed with a metal sheath or tube 3, preferably of iron, plugged at the lower end by a piece-of wood or other material 4, and having a filling 5 of powdered rutile, or a filling of a mixture of a preponderating amount of rutile with some other metal oxids, especially magnetite. The main body 6 of the anode 2, which has nearly twice the diameter of the cathode, is formed of iron, but has a small core 7 of copper or of any other metal which consumes less rapidly than iron. The are is primarily established between the upper edge of the metal sheath 3 of the cathode and the iron of the anode, but is very quickly transferred so as to play between the main body of the cathode, which has a preponderance of rutile, and the anode. A molten pool 8 is promptly formed at the working end of the cathode, While the working end of the anode is only'very slightly eaten away or depressed, as indicated in solid lines. For all practical purposes the working end of the anode may be considered flat, no crater of any consequence forming at this end, and this is due to the presence of the very slowly consuming core of copper, or other suitable material. In the absence of such core there is formed a steep and deep crater as indicated at 9 in dotted lines, and when, upon the interruption of the current, the two electrodes come together, the working end of the cathode often wedges tightly in this crater, so that the ordinary arc-establishing mechanism is not powerful enou h to separate the electrodes and to reestablish the arc. The core 7 prevents the formation of this crater. But this core does not prevent the freezing together of the electrodes when, upon the interruption of the current, the anode makes contact with the pool 8. When the electrodes thus come in contact a small portion of the metal in the workin face of the anode is fused and forms with the pool a honeycombed alloy or mixture of high specific resistance. With the employment of currents of ordinary voltage (110 volts being normally used), the electrodes would remain frozen together, and could not be separated by the ordinary arc-establishing mechanism; but in accordance with my invention, I employ a much higher voltage, up to 220 volts and more, which, discharging between the small interstices of the juncture, forms a. number of minute arcs, which rapidly heat and melt the alloy, whereby the ordinary arc-establishing mechanism is enabled to separate the electrodes.

In the drawings I have conventionally indicated clamps or terminals 10, 11 for the electrodes, and conductors 12, 13, leading therefrom to a suitable source of current 14:. This latter is represented by the conventional sign for a battery, but is intended to cover any suitable source.

What I claim as new and desire to secure by Letters Patent of the United States, is,

1. An are light anode of iron having a core of a metal which consumes slower than II'OII.

2. An are light anode of iron having a core of copper.

3. The combination in a circuit of abnormally high voltage, of an are light cathode formed mainly of metal oxid and a substantially iron anode.

4. The combination in a circuit carrying a current of abnormally high voltage, of an are light cathode formed of a metal tube with a filling in which rutile preponderates, with a metal anode in which iron preponderates.

5. The combination with an are light cathode formed mainly of metal oxid, with an anode of iron having a greater diameter than the cathode and formed with a core of a metal which consumes slower than iron.

6. The combination of an are light cathode formed mainly of metal oxid, with an anode of iron having a greater diameter than the cathode and formed with a copper core.

7. An are light cathode composed substantially of rutile aeked in a metal sheath, eter than the cathode, and formed with a 10 in combination wit an anode of iron havco per core.

ing a reater diameter than the cathode and n witness whereof I have hereunto set provi ed with a core of a metal which conmy hand this tenth day of December, 1907. sumes more slowly than iron. BERTHOLD MON AS011 8. The combination of an are light cathode, consisting of a metal tube filled. with Witnesses: powdered rutlle, with an anode com osed JULIUS RINNLAND, mainly of iron and having a larger iam- HART N. 

